Figure 5.

RNA synthesis of viruses containing mutations at the amino acid position 44. Wild-type virus and mutant viruses containing amino acids N and I, D, and Q, respectively, at the a.a. position 44 were infected into MDCK cells at MOI of 2.5. At 9 hpi, the accumulation levels of viral mRNA (A), cRNA (B), and vRNA (C) were measured by qRT-PCR, and the amounts of these RNAs were normalized by that of cellular actin mRNA. These results are averages from three independent experiments with standard deviations. ^*p < 0.05; ^**p < 0.01.